Clamp for master sheets of printing machines



Allg. 7, 1945. L: H MQRSE 2,381,461

CLAMP FOR MASTER SHEETS OF PRINTING MACHINES L. H. MORSE Aug; 7, 1945.

CLAMP FOR MASTER SHEETS OF PRINTING MACHINES Filed Jan. 1o, v1944 5 sheets-sheet 2 Woran/4^ Aug. 7, 1945.r

CLAMP FOR MASTER SHEETS OF PRINTING MACHINES Filed Jan. l0, 1944 3 Sheets-Sheet 5 INVENToR W wsa.

JAM /`m% Patented Aug. 7, 1945 I CLAMP FOR MASTER SHEETS OF PRINTING MACHINES Lawrence H. Morse, Mentor, Ohio, assignor to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Application January 1o, 1944, serial No. 517.683

9 Claims.

This invention relates to a means for clamping a master sheet on a drum of a printing machine. One of theobjects oi the invention is to provide clamping mechanism which may take a variety of master sheets, whether the same be metal or paper or. other material, and whether they are provided with a row of openings across one end i as is frequently the case) or have the end portion imperforate.

In carrying out my invention, I provide clamps for the leading end and trailing end of the sheet. each of which has provision for securing a sheet by projections'extending through openings therein or by distorting the sheet into a recess, resulting in kinking it, to eiect a. clamping action. The clamping action by means of the projections is well adapted for metal plates, or plates of other material having sufcient thickness of body to enable the sheet to be perforated without danger oi' tearing. On the other hand, the portions of the clamps which effect their holding action by kinking the sheets are especially adapted for thin sheets such as may be made of paper.

My invention is illustrated in a preferred form in the drawings and hereinafter described in detail. As there shown the clamp for the leading end of the sheet is substantially the same as that shown in my pending application No. 504,656, iiled October 2, 1943. The clamp for the trailing end of the sheet, however, is peculiar to the present application, which provides a single clamping member so formed, and cooperating with such an anvil, that they may effectively hold a perforated sheet by means entering the perforations or an imperforate sheet by means pressing it into a recess in the anvil. apparent fromthe following detailed description of the mechanism shown in the drawings.

In the drawings. Fig. 1 is a side elevation, partly broken away,-of a printing drum equipped with my master sheet clamps for holding the two ends of the master sheet; Fig. 2 is a cross section of the drum in a plane indicated by the line 2-2 on Fig. l and showing the clamps closed but without a master sheet on the drum; Fig. 3 is a fragmentary cross sectionvsimilar to Fig. 2 but showing the clamps in the open position; Fig. 4 is a fragmentary cross section of the drum showing the clamps closed on a' thin paper sheet retained by kinking action; Fig. 5 is a similar cross sectional view showing 'the clamps closed in retaining a sheet provided with a row of openings across each end; Fig. 6 is a fragmentary view of a portion of either end of such master sheet as clamped in Fig. 5,

This operation will be more In Figs. 1 to 5, i0 designates a suitable rotary drum having" a segmental recess orl gap l through its periphery. Adjacent one edge of the gap is a ledge adapted to form an anvil for the v clamp to secure the leading edge of the sheet. As shown in the drawings, this ledge is provided by a ilat bar` l5 secured in a radial position to the drum and having an outwardly facing longitudinal recess 6.

The clamping member for the leading end of the master sheet comprises a member having a cross bar 2| longitudinal of thedrum, a central arm 23 pivoted on a shaft 24 mounted in the drum, and a pair of arms 25,v 26 abutting such shaft. The cross bar 2| carries a longitudinal strip which is bent on itself to provide an inwardly extending flange 21 in position to coact with the groove I6. Two or more pins 28 carried by the bar I5 form suitable stops for the inner end of the sheet to be clamped on the drum.` The bar on the clamp is perforated to allow the passage of such pins, so that the sheet may not be inadvertently passed over the tops of thepins. A spring 29 secured to the drum and to the arm 23 tend to maintain the flange 21 in coaction with the ledge |5 to deect a very flexible sheet between them I and effectively clamp it, as illustrated by the sheet designated B in Fig. 4.

I also secure to the cross bar 2| of this clamping yoke a face bar 30 having projecting pins or hooks 3| adapted to extend through openings in a master sheet. l

The construction just described enables the mounting of the leading end of master sheets of various forms. If the sheet has a row of holes through it adjacent the end (as illustrated for example by the sheet A in Figs. 5 and 6) it may readily be hooked over the hooks 3|. If the end portion of the sheet is imperforate. as is frequently the case with a paper sheet, it may be readily clamped by the flanged edge 21 which kinks the end portion of a sheet into the groove I6 as shown in Fig. 4.

To provide ready means to force the clamping member 20 backwardly away from the ledge I5, I mount in such clamping member a threaded sleeve 35 which carries a freely slidable rod 36 abutting the ledge i5. In a bifurcated head on the sleeve I pivot a cam arm 38. When the clamping means .provided by the flange 21 and the ledge I5 is to be idle, the clamping arm 38 is positioned outwardly in alignment with the sleeve -away from the ledge' l E as shown in Fig. 3.

I will now' describe the clamp for the trailing .end of the master sheet. with which the present.

Ninvention is particularly concerned. As shown in `the various views, I have provided at the other edge of the gap in the clamp a stationary clamping ledge or anvil provided by astrip oi.' material doubled on itself at an acute angle thus having a radial portion 4i! secured to the radial face of the drum, and a portion 4I at an acute angle which extends in a direction oi' a chord into the' gap and constitutes yan anvil -for the clamp.

" action with the groove i8 oi' the anvil plate, as

already described. Then when the sheet is wrapped around the drum and the clamp is in the open position shown in Fig. 3, the trailing end is inserted between the anvil and clamp and the clamp allowed to swing inwardly about the rod I l as a pivt (the ends of the slots now abutting The anvil 4i comprises an aligned row or' ilngers spaced by notches 42 correspondingin position to the openingsinthe master sheet to beY clamped. Such a'master sheetis. indicated, for

instance, at A inAFi'g. 6, where itis shown as hav- `ing a scalloped end providing ears a with slotted recesses between ears are idle in the operation of my clamp and the sheet could equally well be uninterrupted across the end'exceptfor the slots a', through which teeth on the clamp may extend. l v

As shown' in each oi the views, the clamping member for the trailing end comprises a cross plate 50 having its ends flanged inwardly at right angles to form arms 5|. Each of these arms has a slot 52 embracing a projecting pin ora cross y rod 53 on the drum'. Secured to thefree mar-- Vgin' of the plate 50 is a' sheet metal strip 55 bent inwardly at right angles and to provide a clamping edge 56 for the paper sheet, this edge being openings a? throughvthem -This is a' form oi'v Y .master sheet-which is inuse, but the scalloping the rodi and 'this brings the-edge 58 into engage-inept with the sheet directly opposite the groovel and kinks thesheet into the groove,

.as shown in Fig. 4. In this position the teeth 58 may press the extreme edge of the sheet inwardlyslightly into the anvil recesses but such .aetienisidie 'eilectthis I provide means to shift one of the clamps lengthwise ofthe drum. This is very Adirectly opposite aligned longitudinal grooves 4.8

in the anvil fingers. On 'the inner side oi the strip 55.15 'a bar 51 having on its inner face a row of inwardly projecting teeth 58 which are located in registration with the notches l2 in the anvil. Tension springs 8U are secured to the clamping plate 50 at their outer ends, and at their inner ends are suitably anchored within the drum. As shown the inner ends are secured to collars BI which for convenience embrace the rod 24 on outwardly in an inclined direction which is partly radial and partly in a general direction toward the anvil, and then when the trailingfend of the sheet has been inserted between the clamp and anvil the clamp is allowed to swing inwardly under its spring action and the teeth pass through the openings in the sheet and the spring brings the sheet and clamp into coaction with the anvil, as shown in Fig. 5.

When clamping a perforate sheet the inwardly turned edge 56 lies against the face of the sheet while the spring SIIpulls the clamp along the anvil to maintain tension on the sheet, the clamp conveniently effected by mounting in the leading clamp a rod which is threaded in the clamp and abuts the ends of the drum. As shown in Fig. l, the arm 25 of the clamp embraces the red lil slidably, while the arm 26 is threaded to coact with threads 'Il on the rod, and thus a turning ci' the rod (as for instance manually by a knurled collar 12 thereon) effects the desired shifting.

within a gap in the drum, a clamping member pivotally and slidably mounted within the drum having inwardly projecting teeth, said clamping member having an inwardly projecting edge beyond the teeththe anvil having a longitudinal groove with which said edge may coact to kink a sheet into the groove, and spring means tending to constrain the clamping member inwardly.

2. 'I'he combination of a drum having an anvil within the gap in the drum, said anvil having a row of openings init, a clamping member pivotally and slidably mounted within the drum having inwardly projecting teeth registering with the openings, said clamping member having an inwardly projecting edge beyond the teeth, the anvil having a longitudinal groove with which the edge may coact to kink a sheet into the groove and imeans to force the clamping member inwardly.

3. The combination of a drum having a gap, an

vanvil in the drum having a longitudinal recess.

at the inner end of its sliding movement, an inward projecting edge on the clamp adapted to coact with the groove when the clamp is at the inner end of the sliding movement and teeth Y on the clamp back oi' said edge and adapted to insuch position having the end of its slot 52 free tions indicated at B in Fig. 4, the leading end is clamped by engagement of the iiange 21 in coan anvil therein having a longitudinal groove,

a clamping plate having slotted end arms, pivots carried by the drum for said arms whereby the clamp may swing inwardly and outwardly and also slide along said pivot, spring means acting diagonally on the clamp to swing it inwardly and slide its slotted arms along the pivot. inwardly projecting teeth on the clamp adapted to engage openings in the sheet and an edge on the clamp adapted to coact with the groove in the anvil.

5. The combination with a drum having a gap, a clamp mounted therein comprising a plate and inwardly flanged ends forming arms, slots through said arms. pivots carried by the drum extending through the slots, the plate being recessed between the arms, the edge of the plate being curled inwardly at the recess to providea nnger grip, spring means acting on the plate tending to constrain it inwardly and to maintain it with the end o! the slots in engagement with the pivots. an inwardly projecting longitudinal edge on the plate. an anvil on the drum with which said edge may coact and inwardly projecting teeth on the clamp.

6. The combinationwith a drum having a gap, a clamp mounted therein comprising av plate and inwardly ilanged ends forming arms, slots through said arms, pivots carried by the drum extending through the slots, an inwardly projecting longitudinal edgeon the plate, an anvil-on the drum having a longitudinal groove with which 'said edge may coact. inwardly projecting' teeth on the clamp in a row behind the clamping edge, and a tension spring anchored at its outrend to the clamp and extending. in an inclined direction with reference to the clamp inwardly of the pivotal axis o! the clamp and attached to the drum beyond such axis.

7. The combination ot a drum having a gap,

an anvil within the gap, a swinging clamping member in the drum having an inwardly lacing clamping portion adapted to coact with the anvil, a row ot teeth on the clamping member out ol' range o! the inwardly facing clamping portion, and spring means acting on the clamping member to constrain it toward the anvil and inwardly across the face of the anvil.

8. The combination of a drum having a gap, an anvil in the drum having a row of openings, outwardly facing aligned grooves in the 'anvil between the openings, a swinging clamping member in the drum having an inwardly lacing clamp-l ing edge adapted -to coact with the grooves and having a row oiinwardly facing teeth being adapted to enter said openings, said teeth being formed into hooks with their openings away from said clamping edge, and a spring means acting on the .clamping member to constrain it toward the anvil.

9. The combination oi a drum having a gap. an ganvil in the drum having a longitudinal groove `on its outer tace. a clamping member pivotally and slidably mounted within the drum. an inwardly projecting edge on the clamp adapted to coactwlththegrooveintheanviltokinka sheet between them, and teeth on the inner tace of the clamp between the clamping edge and the pivot oi the clamp adapted to occupy open- 30 ings in a sheet, and spring means acting on the clamp inl a direction to constrain it inwardly toward the anvil and inwardly across the lace ofthe anvil.

LAWRENCE H. MORSE. 

